Heat treating apparatus



Oct. 27, 1964 c. F. ALBAN 3,154,621

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IN VEN TOR.

United States Patent 3,154,621 HEAT TREATING APPARATUS Clarence F.Alban, Allen Park, Mich, assignor, by mesne assignments, to W. M. ChaseCompany, a corporation of Delaware Filed Apr. 18, 1961, Ser. No. 103,9151 Claim. (Cl. 2665) This invention relates to heat treating apparatus,and more particularly to a furnace for heat treating a continuous flowof parts.

It is an object of the present invention to provide an improved treatingmechanism which is capable of continuously feeding and heating a widevariety of objects.

Another object is to provide an improved heat treating furnace which iseconomical to manufacture, operate and maintain.

The present invention acomplishes the above objects by providing afurnace chamber adapted to enclose a spiral ramp elevator of a verticalvibratory feeder operative to feed objects vertically through thefurnace chamher so that a continuous flow of the objects may be heatedtherein while being transported therethrough.

In the accompanying drawing:

FIG. 1 is an elevational view of a heat treating furnace constructed inaccordance with the present invention, with the furnace shown in theopen position thereof and taken partially in section on the line 1-1 ofFIG. 2; and

FIG. 2 is a top plan view of the heat treating furnace of FIG. 1illustrating the open and closed positions thereof.

Referring to FIG. 1, the heat treating apparatus of the inventionincludes a vibratory feeding mechanism 1%) of known construction, suchas the vertical-vibratory spiral feeders of either the ES or RVES modelseries manufactured by Syntron Company of Homer City, Pennsyl- Vania. Byway of illustration, the disclosed form of vibratory feeder includes avibrator drive mechanism 16 which is mounted upright by means of asuitable shock absorbing cushion 13 on a support 20. A vertical column22 is mounted on the top of vibrator 16 for supporting a ramp 24 woundhelically therearound. The above vertical vibratory spiral feeder can besupplied with two different forms of known drives, eitherelectromagnetic or rotary vibratory. Vibratory 16 is shown as theelectromagnetic type of drive unit and is electrically powered forproducing high speed electro-magnetic vibrations (3600 vibrations perminute) which are transmitted via column 22 to ramp 24, the vibrationalmotion of ramp 24 causing objects received on the surface of the ramp toflow up the ramp. This type of vibratory feeder is available withrheostat or reactor controls for controlling the rate of elevation orflow of material in the ramp. Such controls may be incorporated in asuitable control box 26 (shown only in FIG. 1) and connected by leads 23to the vibrator mechanism 16. Vibrator 16 may also comprise a slowerspeed rotary vibrator type of drive unit when it is desired to handlelarger, higher spirals at greater capacities than is possible with theelectromagnetic type. With the rotary type, the control of the rate ofmaterial how and adaptability to dilferent materials is accomplished byadjusting the thrust angle of the rotary vibrator.

The present invention combines the above conventional vertical vibratoryfeeder it with a furnace 12 to provide an improved heat treatingapparatus. One half of furnace 12 includes a semi-cylindrical outercasing 3% which is closed at the ends thereof and supportedindependently of the feeding mechanism by legs 32 so as to be isolatedfrom the vibratory motion thereof. Disposed concentrically within outercasing 30 is a semi-cylindrical inner casing 34 which is made of heatresistant metal or suitable refractory material, depending upon thetemperature ranges to be used in the heat treatment. An insulatinglining 36, also made of suitable heat resistant material, is providedbetween outer and inner casings 30 and 34. A semi-cylindrical doorstrpcture 38 forms the other half of furnace l2 and comprises outer andinner casings 4t) and 42, respectively identical in shape to casings 30and 34, as well as a refractory lining 44 located between casings 3t}and 34. Door 38 is pivotably connected to outer casing 3t) along onevertical side edge thereof by three hinges 4s. Semi-circular openings 48and 50 are provided in the respective bottom portions of the fixedcasings 3t 34 and the door 33 so that when door 38 is swung to itsclosed position (indicated in dashed lines in FIG. 2) a circular centerhole is provided for receiving column 22. Each of the furnace openings48 and St) has a semi-cylindrical liner 51 affixed thereto which is madeof suitable soft, heat resistant material to provide an insulating sealbetween column 22 and the furnace openings which neither transmits norrestricts the vibratory motion of the column.

When furnace 12 is closed, complemental inner casings 32 and 42 form anannular heating chamber 52 concentrically surrounding and completelyenclosing spiral ramp 24. Chamber 52 is heated by suitable heatgenerating means such as a co-axial series of electrical heating elementcoils 54 suspended on a stringer conduit 55 adjacent the inner surfacesof casings 34 and 42. Heating element 54 is energized via leads enclosedin conduit 55 which are coupled through control box 26 to a suitablesource of electrical power. A fan 58 is suspended in the fixed half offurnace 12 near the top of chamber 52 by a shaft ea journalled in thetop ends of casings 30 and 34. Fan shaft 60 is driven by an electricmotor 62 which is energized via leads 64 also coupled through controlbox 26 to the source of power.

A gravity input chute 66 is mounted in and extends through an opening inthe furnace wall to feed objects such as small metal parts from outsidethe furnace into a receiving hopper d3 supported on column 22 inside thefurnace chamber. An inclined discharge chute 70 is supported with itsupper end beneath the upper, outlet end 25 of ramp 24 so as to receiveparts discharged therefrom. Chute '74) also extends through an openingin the wall of the furnace and delivers the parts by gravity to a hopperor conveying apparatus, not shown.

In operation, the furnace is closed and then heating element 54 isenergized automatically by suitable thermostatic controls located incontrol box 26 and connected in a known manner to provide automatictemperature control. Motor 62 is also energized whereupon fan 58 blowsheated air downwardly along the spiral ramp 24 in a direction oppositeto the flow of parts therein. The circulating air is reheated as itreturns upwardly along the coils of heating element 54. Vibrator 16 ofthe feeder is then automatically or manually energized to causevibratory motion of spiral ramp 24, and objects such as small metalparts are fed via chute 66 to hopper 68. The vibratory motion of ramp 24causes the parts to climb up the ramp, the parts being heated to adesired temperature for a desired period of time in accordance with thecontrollable rate of feed of the feeder mechanism and the controllableair temperature within chamber 52. As the heated parts reach upper end25 of ramp 2d they drop into discharge chute 70 and are delivered viagravity to the exterior of the furnace.

The above described heat treating apparatus permits a rapid, continuousstream of parts to be heat treated without interruption of their travelto and from chutes 66 and 7t). By utilizing a vertical vibratory feedercombined with a concentrically enclosing furnace chamber,

a compact arrangement is obtained which occupies a minimum of fioorspace. Inasmuch as the parts are conveyed entirely by ramp 24 and chutes66 and 70, there are no working mechanical parts, such as motors, gears,sprockets, chains, buckets, speed changers or the like to be adverselyafiected by the heat of the furnace. The flow of parts in the ramp canbe stopped, blocked or choked without any damage to the equipment, andthe provision of the hinged door 38 allows immediate access to theentire ramp so that such stoppages may be easily cleared. Because of thelarge surface area of the spiral ramp contained within the relativelysmall concentric heating chamber 52, economic and efiicient heating ofthe parts can be accomplished by radiation as well as by the reverse airflow created by fan 58.

It is to be understood that it is within the scope of the presentinvention to utilize a suspension mounting of the vertical vibratoryfeeder wherein a vertical spiral ramp enters the furnace from the topthereof rather than at the bottom as disclosed. Moreover, the flow ofparts may be reversed so that they are lowered by the spiral ramp duringtheir passage through the furnace chamber, and likewise the flow of airmay be directed in either direction along the spiral ramp by merelyreversing motor 62.

I claim:

Apparatus for continuously heat treating small metal parts comprising afixed casing having insulated top, bottom and upright side wallsdefining an oven chamber therein, a vibratory feeder mechanism supportedindependently of said casing including a vibrator positioned outsidesaid casing and a column extending vertically therefrom into said ovenchamber, said casing having an opening in one of said top and bottomwalls adapted to receive said column therethrough, insulating meansinterposed in said opening between said column and said casing for heatscaling said opening, a helical ramp supported on said column entirelywithin said chamber and having an inlet and an outlet spaced verticallyfrom one another therein, electrical heating means including a series ofheating elements positioned between said helical ramp and said side wallof said casing and at least partially surrounding substantially theentire length of said ramp, said side wall of said casing including adoor section hinged thereto for lateral swinging movement about avertical axis, said door having a horizontal dimension larger than thediameter of said ramp to facilitate access to and installation of saidramp in said chamber, and means extending through said side wall of saidcasing for delivering the parts to the inlet and from the outlet of saidramp whereby objects are heat treated while being transported on saidramp in response to operation of said vibrator and said heating means.

References Cited in the file of this patent UNITED STATES PATENTS1,043,158 Simmons Nov. 5, 1912 1,073,912 Koch Sept. 23, 1913 2,283,798Delano May 19, 1942 2,557,379 Hancock et al June 19, 1951 2,615,702Allert Oct. 28, 1952 2,658,286 Spurlin Nov. 10, 1953 2,662,851 Jones etal Dec. 15, 1953 2,688,807 Ginther Sept. 14, 1954 2,918,070 Carrier Dec.2, 1959 2,965,368 Mcllvried Dec. 20, 1960 3,032,409 Richelson May 1,1962

